Table of Contents
International Journal of Microwave Science and Technology
Volume 2010, Article ID 871027, 5 pages
http://dx.doi.org/10.1155/2010/871027
Research Article

High-Frequency Properties of Embedded Passives and Thermal Resistance in Organic Substrates for RF Module

1Tsukuba Research Laboratory, Hitachi Chemical Co., Ltd., 1500 Ogawa, Chikusei-shi, Ibaraki 308-8521, Japan
2Central Research Laboratory, Hitachi Ltd., 1-280 Higashikoigakubo, Kokubunji-shi, Tokyo 185-8601, Japan

Received 30 October 2009; Accepted 8 February 2010

Academic Editor: Marc J. Franco

Copyright © 2010 Yusuke Kondo et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Radio Frequency (RF) modules have been miniaturized to meet the demand for smaller and more enhanced handsets for wireless applications such as cellular phones. However, area for passive devices used in RF modules has made further miniaturization difficult. Passives embedded in substrates are now being studied intensively. In addition, circuit simulation technology has been developed that enables efficient designing of RF module circuits. Circuit designers, however, have limited database of organic substrates and embedded passives. Further, optimized thermal designs are required to prevent thermal resistance increase due to miniaturization of substrates. In this paper, we describe the high-frequency properties of the capacitors embedded in the organic substrates and present the equivalent circuit models of the embedded capacitors. We also present the thermal design of organic substrates applicable to RF modules.